Bulldozer attachment for tractors



July 10, 1951 f E: EX N 2,559,816

BULLDOZER ATTACHMENT FOR TRACTORS Filed Dec.'l2, 1946 3 Sheets-Sheet l arwe/rytm -E. C. ALEXANDER July 10, 1951 E. c. ALEXANDER BULLDOZER ATTACHMENT FOR TRACTORS s She ets-Sheet 2" Filed Dec. 12, 1946 grwe/Mov E- C. ALEXANDER gwg/gm July 19, 1951 v E. c. ALEXANDER BULLDOZER ATTACHMENT FOR TRACTORS s sheets-Sheet s Filed Dec. 12, 1946 E. C. ALEXANDER Patented July 10, 1951 BULLDOZER ATTACHMENT FOR TRACTORS Everett 0. Alexander, Oharlottesville, Va., assignor to Southern Welding & Machine Compa a partnership reinia Application December 12, 1945.:SerialNo; 715,660 3 Claims. (01.312144) This invention relates to a bulldozer attachment for tractors, of the general type which comprises. a frame attachable to the tractor, ex-, tending forwardly from the rear axle, an earth moving blade carried by the frame adjustable about a vertical axis for angling and about a horizontal axis for tilting, with hydraulic means for operating theblade.

One of the objects vof the present inventionis to provide a bulldozer attachment of the type described, consisting of a fixed frame for attachment to the tractor, and a movable blade lifting framepivotally mounted on the fixed frame at an intermediate point in the length of the tractor, so that the rear portion of the frame does not oscillate and come into interference with fixed structure associated with the tractor.

Another object of the invention is to provide a tractor attachment particularly adapted for wheeled tractors, in which the pivoted frame is upwardly arched at the sides so as to clear the steering wheels with minimum lift of the blade when the steering wheels are angularly deflected.

A further object of the invention in a bulldozer attachment of the character described is the provision of a single hydraulic ram located in the medial longitudinal plane of the frame structure, reacting between the fixed and movable frames to raise the latter in the blade lifting operation.

Another object of the invention is the provision of similar and adjacent means between the movable frame and blade for adjusting the latter in various positions for tilt and angling.

Other objects of the invention will appear as the following description of a preferred and practical embodiment thereof proceeds.

In the drawings which accompany and form a part of the following specification:

Figure 1 is a side elevation showing an embodiment of the invention, installed on a tractor;

Figure 2 is a top plan view;

Figure 3 is a front end elevation;

Figure 4 is a plan viewof the front end of the movable framashowing the blade in angling position of adjustment, part of the movable frame being shown in section;

Figure 5 is a rear view of the blade in angling position, showing the means for effecting tilting adjustment, parts being shown in section;

Figure 6 is a longitudinal view partly in vertical section, illustrating one of the duplicate means for making the angling tilting adjustment, the view being taken along the line 6.6 of Fig ure2;

Figure 7 is a vertical section through the univ rs lioint nd b d Referring now in detail to the several figures, the ,num e1'al I represents a tractor which is of the wheeled type, having the front steering wheels 2 which steer about a central vertical axis. The numeral 4 represents the rear axle housing. The side frame members of the tractor are shown at "5. The tractor is assumed to be equipped-with the conventional hydraulic system operated through the power plantof the-tractor, saidhydraulic system being not shown.

.The bulldozer attachment constituting the present invention comprises a fixed frame 6, havingspaced parallel side members '1, connected at their front to the lower ends of an upright structure which includes the side beams .8, ar ranged symmetrically withrespect to the medial longitudinal vertical plane of the fixed frame, having ,lower vertical parallel portions .9, intermediate -upwardly convergent portions l8, and upper closely spaced parallel portions H, joined at the top bya stout pin {2, whichbridges the space between them.

'The side frame members 1 have substantially horizontal forward portions !3, anddownwardly inclinedrear portions M. The spacing of the side frame members l is such that their forward longitudinal portions contact the side frame members of the tractor, and the length of the forward portions is such that when the fixed frame is positioned on the tractor with the on right structure immediately forward of the front of the tractor, said forward portions terminate at .-about-the middle of the length oftheside frame o f the tractor. The side framemembers 7 are, bolted to the tractor frame at these points and also at pqitltsiforwardly thereof. The rear ends of the side frame members "I are bolted to brackets lfiyfixedto the rear axle housing l. There is some slight longitudinal play. in thebolt connections of; the fixed frame 6 with the tractor frame, ;-so, that rearwardly acting load stresses communicated-to thefixed frame 6 are referred to the -rear axle housing, relieving all parts of the tractor-forward of the'rearaxle-housing from such; stresses.

Thegsidegmembers 'l of the .fixed frame have outwardlyextendingbrackets l6, formed withside flanges l1 parallel to the side members 1 and spaced therefrom, the spaces being bridged by pivotpins l8, secured to said flanges and to the adjacent, side. members, said pivot pins ,bei-ng coe axial.-

- A1 movable v frame 19 l is carried. .by the fixed frame 6, comprising parallel side arms 20, hinged at their rear ends on the pins l8, extended forwardly beyond the fixed frame, and being fixed at their front ends to an arcuate thrust beam 2|, which carries the blade 22. The side arms 20 are downwardly curved toward their outer ends forwardly of the steering wheels 2, those portions of said side arms which lie laterally of said steering wheels being substantially at the level of the tractor frame when the blade is working below ground level, so that only a short lift of the movable frame is required to provide clearance for the steering wheels beneath the side arms, when the steering wheels are in laterally turned positions.

A hydraulic ram has a cylinder 24 hingedly connected to the pin l2, at the top of the upright member of the fixed frame, and a plunger 24' pivotally connected to a pin 25, which is mounted through a bifurcated lug 2B, rising from the middle portion of the thrust beam.

The thrust beam 2!, in the form. shown, is a fabricated member consisting of spaced congruent upper and lower crescent shaped plates 21, one of which is shown in plan in Figure 4, having an arcuate plate 28 welded across the front, and a similar but narrower plate 29 welded between the plates 21 at the back, forming a boxlike structure. Said plates 28 and 29 terminate short of the ends of the crescent shaped plates 21, leaving the ends open and longitudinally bifurcated, one of said ends being shown in section at 21 in Figure 6.

v A bolt 30 extends forwardly through the back and front plates 29 and 28 in the medial vertical I plane of the thrust beam 25, rotatable in apertures in said plates and forming the horizontal axis about which the blade 22 tilts. The forward end of said bolt is secured as by welding, to a lug 31, having spaced parallel furcations 32. The blade, midway of its length, carries a fixed plate 33 with projecting spaced parallel lugs 35 between which the furcations 32 fit. A bolt 35 passes through aligned apertures in the lugs 34 and furcations 32 and forms the axis about which the blade 22 angles. The bolts 38 and 35 and the structure with which they are immediately associated constitute a universal joint.

The means of adjusting the blade for angling and tilting will now be described. Adjacent each end the blade 22 is provided with a vertical series of uniformly spaced parallel projecting plates, those at the right, viewing the blade from the rear as in Figure 5, being designated as 36, 3'1, 38 and 39, corresponding plates at the left being denoted as 36, 3'1, 38 and 39. These series of plates respectively cooperate with connecting struts 40 and 41, carried by the respective ends of the thrust beam 2 I. Each of these'struts is composed of telescopic pipe sections whereby the length of the struts may be increased or diminished. Each comprises a pipe section 42, of large diameter, having its inner end within one of the open bifurcated ends 21 of the thrust beam 2|. It is hingedly mounted at its inner end to swing in a horizontal plane, by a bolt 43, which passes vertically through aligned holes in the plates 21 and pipe section 42. Said pipe section at an intermediate point in its length has a pair of aligned holes through which a locking bolt 45 passes, said bolt being a plain cylindrical bar having a bent upper end serving as a handle and to prevent it from slipping through. A pipe section 44 of smaller diameter telescopes within the pipe section 42 and has in its upper walls, series of diametrically aligned holes which can be selectively aligned with the holes in the outer pipe section so that the strut can be locked in position of length adjustment by means of the bolt 45. Gross tolerance is provided in the fit of the bolt within the aligned holes, so that the bolt can be readily inserted and withdrawn, notwithstanding accumulation of rust thereupon incident to exposure to the elements and long periods of disuse; also to allow slight rotation of the smaller pipe section.

The exposed end of the inner pipe section 44 carries a bifurcated fitting 45, having parallel lugs 4] spaced apart sufiiciently to embrace any adjacent two of the plates in the vertical series of plates carried by the blade, with enough tolerance to permit tilting of the lugs 47 with respect to the embraced plates, as shown in Figure 5. The plates in both said vertical series have aligned apertures therethrough, and the lugs also have aligned apertures which can be brought into alignment with the apertures in said plates so that the lugs and plates can be connected by bolts ifiisimilar to the bolts @5. There is considerable tolerance in the fit 0f the bolts 45 in the aligned apertures to permit the relative tilt of the plates and lugs shown in Figure 5.

To adjust the blade with no tilt, the struts it! and ii are positioned with the lugs a? embracing the middle pairs of plates 37, 38, and 3? and 38, respectively. To tilt the blade with the right end up, the adjustment is as shown in Figure 5, with the lugs of the righthand strut embracing the lower pair of plates 38 and 39 in the righthand series, while the lugs of the lefthand strut embrace the upper pair of plates and 37' in the lefthand series. To tilt the blade in the opposite direction, the lugs on the respective struts would be made to embrace the lower pair of plates 38 39 on the left and the upper pair of plates 36, 3'! on the right.

When it is desired to operate with each end of the blade in a vertical plane perpendicular to the direction of travel, the bolts i5 are removed from the struts, the blade put in the desired position and the bolts inserted through such holes as may be in alignment. Both struts will be of equal length in this case. To adjust the blade for angling, it is moved to the desired position while the bolts &5 are not in place, and the bolts reinserted in the then aligned holes to lock the struts in adjusted position. In angling positions of the blade, the struts will be of unequal length, both sides of the plate being rigidly supported.

, The rotary play of the small pipe sections M- in the large pipe sections 52, incident to the loose fit of the bolts '15 in the apertures through which they extend, together with the tolerance in the spacing of the lugs 47 with respect to the pairs of plates in the vertical series which they embrace, as well as the loose fit of the bolts &8, gives sufficient aggregate freedom of movement to permit the practical range of tilting and angling for which the bulldozer attachment is desired.

While I have in the above description disclosed what I believe to be a preferred and practical invention, characterized by simplicity of construction and facility of adjustment, it will be understood by those skilled in the art that the specific details as shown and described are illustrative and not to be construed as limiting the scope of the invention.

What I claim as my invention is:

1. In a wheeled tractor of the type having,

a hydraulic power take-off, a bulldozer attachment therefor comprising a fixed frame having spaced parallel side members adapted to fit against the tractor side frames, to be secured at their rear ends to the rear axle of the tractor and to be bolted to said tractor side frames with longitudinal lost motion permitting stresses to be transferred through the side members of said fixed frame to said axle substantially independent of said tractor side frames, and an upright structure rigidly secured to the front ends of said side members; a movable frame comprising a pair of side arms pivotally mounted to said fixed frame at intermediate points in the length of the side members of said fixed frame on a common transverse axis, and arched downwardly forward of the front wheels, and a transverse thrust beam rigidly connected to the forward ends of said side arms; a single hydraulic ram including a cylinder and plunger rod, hingedly connected to the middle of said thrust beam and of said upright structure, and a blade mounted for universal movement on the front of said thrust beam.

2. In a wheeled tractor of the type having dirigible front wheels, parallel side frames, and a hydraulic power take-off, a bulldozer attachment therefor comprising a fixed frame having spaced parallel side members adapted to fit against the tractor side frames, to be secured at their rear ends to the rear axle of the tractor and to be bolted to said tractor side frames, and an upright structure rigidly secured to the front ends of said side members; a movable frame comprisin a pair of side arms pivotally mounted to said fixed frame at intermediate points in the length of the side members of said fixed frame on a common transverse axis, and arched downwardly forward of the front wheels, a transverse thrust beam rigidly connected to the forward ends of said side arms; a hydraulic ram including a cylinder and plunger rod, hingedly connected to the middle of said thrust beam and of said upright structure, and a blade mounted for universal movement on the front of said thrust beam, said thrust beam being of girder construction including spaced top and bottom plates in horizontal planes, and front and back plates therebetween, said top and bottom plates extending beyond the front and back plates at the ends of the beam, defining open sided bifurcations, and struts pivotally mounted in said bifurcations divergent toward said blade and connected thereto.

3. In a wheeled tractor of the type having dirigible front wheels, parallel side frames, and a hydraulic power take-off, a bulldozer attachment therefor comprisin a fixed frame having spaced parallel side members adapted to fit against the tractor side frames, to be secured at their rear ends to the rear axle of the tractor and to be bolted to said tractor side frames with longitudinal slippage in its connection with said tractor side frames with longitudinal lost motion permitting stresses to be transferred through th side members of said fixed frame to said axle substantially independent of said tractor side frames, and an upright structure rigidly secured to the front ends of said side members; a movable frame comprising a pair of side arms pivotally mounted to said fixed frame at intermediate points in the length of the side members of said fixed frame on a common transverse axis, and arched downwardly forward of the front wheels, a transverse thrust beam rigidly connected to the forward ends of said side arms; a single hydraulic ram including a cylinder and plunger rod, hingedly connected to the middle of said thrust beam and of said upright structure, and a blade mounted for universal movement on the front of said thrust beam, said thrust beam having bifurcated ends, and struts pivotally mounted in said bifurcated ends divergent toward said blade and pivotally connected thereto.

EVERETT C. ALEXANDER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,776,788 Gettelman Sept. 30, 1930 1,834,822 Boling Dec. 1, 1931 1,890,228 Miller Dec. 6, 1932 1,989,431 Stamm Jan. 29, 1935 2,162,993 Austin June 20, 1939 2,187,072 Le Bleu Jan. 16, 1940 2,190,452 Kerber Feb. 13, 1940 2,287,152 Waldecker June 23, 1942 2,314,475 Bird et al. Mar. 23, 1943 2,334,374 Austin Nov. 16, 1943 

